My fins are chipped as well and im running 12-13lbs of boost on a VERY old turbo.
Although i have alot of shaft play i dont smoke or burn oil. I still worry about the fact that the turbo's fins are unbalanced but i doubt that it will cause any drastic problems with boosting.
Just keep an eye on it and check it once a week just in case
Ive got a bigger problem, my c pin for the wastegate arm has gone missing and my wastegate arm pops off randomly under boost causing my wastegate flapper to stay open so i cant build boost. Causing me to have to limp the car to my destination and wait for it to cool down just to place the arm back on the flapper, its a real pain in the ass.